Garvagh Glebe Windfarm

Peat Stability

AGL Consulting were geotechnical consultants to ESB International for the construction of 13 No. Vestas V80/2MW turbines, over 7 km of site access track and a substation on an upland blanket bog on Corry Mountain near Drumkeeran, Co. Leitrim. Our scope of work included the following:

• Detailed forensic investigations into the causes of peat slides that occurred during construction, including undisturbed peat sampling, specialist in-situ and laboratory shear strength testing, slope stability and finite element analysis.
• Developing and implementing integrated peat stability risk assessment, mitigation and certification procedures for the project to advance the current best practice guidelines from the Scottish Executive and to comply with the best practice ICE guidelines for Managing Geotechnical Risk.
• Advising on mitigation measures to minimise the risk of peat instability during construction including realignment and method of construction of access tracks, micro-siting of turbines, methods of peat excavation, and control of spoil.
• Attending multi-disciplinary peat stability risk workshops for peer review and consensus risk assessment of peat stability by independent specialist consultants on hydrology, ecology and geotechnics.
• Developing and evaluating advanced analytical design and testing procedures for floating roads in sensitive areas on peat, including bearing capacity calculations, slope stability and finite element analysis, and full scale serviceability and proof load testing for certification.
• Reviewing and certifying Contractor’s method statements and carrying out site inspections of work during construction.